Metal casting processes, and in particular aluminum and magnesium casting processes, are often used to create a finished object having a hollow interior cavity. This is done primarily to reduce the weight of the finished article and to reduce cost by conserving casting material.
Hollow interior cavities are formed by placing a core in a casting mold prior to introducing the molten metal. After the molding operation, the core is removed by either disintegration (in the case of resin bonded sand cores), melt-down (in the case of metallic cores) or other techniques known to those skilled in the art. This core removal process is time consuming and sometimes expensive depending upon the type of core material used and the removal process employed.
Another drawback of this metal casting process is that the interior cavity must be partially exposed or else a passage must be provided for removal of the core after the casting process is complete. Therefore, the design of the interior cavity shape and placement of the cavity are often dictated more by considerations of core removal than of application and performance of the article in use. Furthermore, while the prior art hollow interior cavity is effective in reducing weight and material costs, it provides no structural support to the article.